Answer:
38g of Cr
Explanation:
Step 1:
The balanced equation for the reaction:
2K + CrBr2 —> 2KBr + Cr
Step 2:
Determination of the masses of K and CrBr2 that reacted and the mass of Cr produced from the balanced equation.
This is illustrated below:
Molar mass of K = 39g/mol
Mass of K from the balanced equation = 2 x 39 = 78g
Molar Mass of CrBr2 = 52 + (80x2) = 212g
Mass of CrBr2 from the balanced equation = 1 x 212 = 212g
Molar Mass of Cr = 52g/mol
Mass of Cr from the balanced equation = 1 x 52 = 52g
From the balanced equation above,
78g of K reacted with 212g of CrBr2 to produce 52g of Cr.
Step 3:
Determination of the limiting reactant.
This is illustrated below:
From the balanced equation above,
78g of K reacted with 212g of CrBr2.
Therefore, 57g of K will react with = (57 x 212)/78 = 154.92g of CrBr2.
From the above calculation, we can see that a lesser mass (i.e 154.92g) than what was given ( i.e 199g) of CrBr2 is needed to react completely with 57g of K. Therefore, K is the limiting reactant and CrBr2 is the excess reactant.
Step 4:
Determination of the mass of Cr produced by the reaction.
In this case, the limiting reactant will be use because it will give the maximum yield of Cr as all of it is used up in the reaction process. The limiting reactant is K and the mass of Cr produced is obtained as follow:
From the balanced equation above,
78g of K reacted to produce 52g of Cr.
Therefore, 57g of K will produce = (57 x 52)/78 = 38g of Cr.
Therefore, 38g of Cr is produced from the reaction.
Is the same reactant always the limiting reactant?
What is the oxidation half-reaction for this unbalanced redox equation? cr2o72– + fe2+ → cr3+ + fe3+ cr3+ → cr2o72– cr2o72– → cr3+ fe3+ → fe2+ fe2+ → fe3+?
Answer:
6Fe^2+(aq) -------> 6Fe^3+(aq) + 6e
Explanation:
The balanced oxidation half equation is;
6Fe^2+(aq) -------> 6Fe^3+(aq) + 6e
A redox reaction is actually an acronym for oxidation-reducation reaction. Since the both reactions are complementary, there can't be oxidation without reduction and there can't be reduction without oxidation.
The main characteristic of redox reactions is that electrons are transferred in the process. The number of electrons transferred is usually deduced from the balanced reaction equation. For this reaction, the balanced overall reaction equation is;
Cr2O7^2–(aq) + 6Fe^2+(aq) +14H^+(aq)→ 2Cr^3+(aq) + 6Fe^3+ (aq) + 7H2O(l)
It is clear from the equation above that six electrons were transferred. Thus six Fe^2+ ions lost one electron each in the oxidation half equation as shown in the balanced oxidation half equation above.
How many grams of CO2 are produced from the burning of 1.0 mol of amyl alcohol, C5H11OH?
Answer:
220g of CO2
Explanation:
Step 1:
The balanced equation for the reaction.
2C5H11OH + 15O2 —> 10CO2 + 12H2O
Step 2:
Determination of the number of mole of CO2 produced by burning 1 mole of C5H11OH.
From the balanced equation above,
2 moles of C5H11OH produced 10 moles CO2.
Therefore, 1 mole of C5H11OH will produce = (1 x 10)/2 = 5 moles of CO2.
Therefore, 5 moles of CO2 is produced from the reaction.
Step 3:
Conversion of 5 moles of CO2 to grams.
Molar mass of CO2 = 12 + (2x16) = 44g/mol
Number of mole of CO2 = 5 moles
Mass of CO2 =...?
Mass = mole x molar mass
Mass of CO2 = 5 x 44
Mass of CO2 = 220g.
Therefore, 220g of CO2 were obtained from the reaction.
In general, when a substance changes from a solid to a liquid,
A.
the density of the substance increases.
B.
the substance no longer has density since density is a property only solids have.
C.
the density of the substance decreases.
D.
the density of the substance remains the same.
Answer:
c,density is the measure of compactness in a substance. Liquid particles are close together however they aren't as close as the particles in solids.
Which one is it? Please help
Answer:
Chemical properties can be tested without changing the substance
Explanation:
what is the correct formula for the compound platinum (vi) flouride?
Answer: PtF6
Explanation: is one of seventeen known binary hexafluorides.
How many grams of KF are in 2 liters of a 3.0 M solution of KF
Answer:
mass ( g ) = 348 g
Explanation:
First you know : M = mole / volume (L)
in question you have the M and V and the formula of SUBSTANCE ( KF )
first you get the number of mole from equation above
so 3 = no of mole / 2
no of mole = 3 × 2 = 6 moles
and the moles equation is no of moles = mass ( g ) / molecular weight ( g/mole )
so you have already calculate the moles and you can know the MW from the Question
Mw of KF = 39 + 19 = 58
so n = mass / MW
so 6 = mass / 58
mass ( g ) = 348 g
GOOD LUCK
In most mirrors, the virtual image appears to come from behind the mirror. True False
Answer
False
Explanation:
why is the international space station in orbit
Answer:
The ISS provides a location in the relative safety of low Earth orbit to test spacecraft systems that will be required for long-duration missions to the Moon and Mars.
Explanation:
Wax is a nonpolar substance . In which type of substance is it the most soluble ?
Answer:
nonpolar
Explanation:
Use the phrase "like dissolves like"
- Hope that helps! Please let me know if you need further explanation.
Most solutions are ___ solutions.
A heterogeneous
B saturated
C static
D unsaturated
Answer:
the answer is A heterogeneous solutions
Explanation:
Mixtures in two or more phases are heterogeneous mixtures. Examples include ice cubes in a drink, sand and water, and salt and oil. The liquid that is immiscible form heterogeneous mixtures. A good example is a mixture of oil and water.Jun 26, 2019
Balance equation: _NO + _H2O = _NH3 + _O2
Answer:
4NO + 6H2O = 4NH3 + 5O2
Explanation:
Think about it this way: there are 4N's 4O's and 12H's and 10O's on both sides that's what makes it balanced
Hope this helps :)
what started the wildfires
Answer:
It is a typical fires that started out of a lightning strike, or people carelessly starting it, or accidentally, or even arson, that went un-noticed and got out of hand.
Answer:
Explanation:
Forest fires always start by one of two ways - naturally caused or human caused. Natural fires are generally started by lightning, with a very small percentage started by spontaneous combustion of dry fuel such as sawdust and leaves. On the other hand, human-caused fires can be due to any number of reasons.
How might an antioxidant prevent another element from gaining or losing an electron?
Answer:
An antioxidant helps in the mopping up and elimination of free radicals and a common example is Glutathione. Oxidation reactions Involves the transfer of electrons or addition of oxygen to a substance.
Antioxidants help in decreasing or prevention of the oxidation of the molecules due to free radicals being formed which causes damage in the cells of animals.
Which 1.0 M solution has the lowest pH?
A.
HCN
B.
H3PO4
C.
H2C2O4
D.
HCl
Which options identify what the arrows in the diagram
represent? Check all that apply.
D atoms
elements
energy
gas
particles
Answer:
D
Explanation:
46g of a mineral contained 16g copper, 14g iron and 16g sulphur. Calculate the empirical
formula of the mineral.
Answer:
CuFeS2
Explanation:
Calculate the moles of each substance by doing moles= mass/relative atomic mass. you should get 0.25 moles of copper and iron and 0.5 moles of sulfur. Then divide all of those numbers by 0.25 (as its the lowest value) you should get 1 for copper and iron and 2 for sulfur. This represents the ratio that they are in within the mineral.
mutations that neither benefit nor harm the organism have (blank) effect on the organisms survival
Answer:
I would say that the mutation has no effect on the organism, as it doesn't help or harm it.
hope this helps :)
Explanation:
Answer:
its a neutral
Explanation:
i did the test
If I add water to 100mL of a 0.15M NaOH solution until the final volume is 150mL, what will the molarity of the diluted solution be?
A. 0.100M
B. 1.2M
C. 0.01M
D. 52.8M
Answer : A
0,15 moles of NaOH -------in-------1000ml
x moles of NaOH ---------in-------100ml
x= 0,015 moles of NaOH
final volume =150ml
0,015 moles of NaOH -------in------150ml
x moles of NaOH ------in--------1000ml
x= 0,1 moles of NaOH
5) Usted empuja muy fuerte un escritorio pesado e intenta moverlo. Usted efectúa trabajo sobre el escritorio: a.- Ya sea que lo mueva o no, siempre y cuando usted ejerza una fuerza. B.- Sólo si el escritorio se mueve. C.- Sólo si el escritorio no se mueve. D.- Nunca; el escritorio hace trabajo sobre usted. E.- Ninguna de las anteriores. ME AYUDAN PORFA?
Answer:
5) You push hard on a heavy desk and try to move it. You do work on the desk: A.- Whether you move it or not, as long as you exert a force. B.- Only if the desktop moves. C.- Only if the desktop does not move. D.- Never; the desk does work on you. E.- None of the above. CAN YOU HELP ME?
B.- Only if the desktop moves.
Explanation:
No work is done if a force is exerted but no displacement occurs. A force perpendicular to the displacement does no generate work.
What is the percentage composition of cobalt in cobalt(II) fluoride, CoF2?
Answer:
60.8%
Explanation:
We'll begin obtaining the molar mass of cobalt(II) fluoride, CoF2. This can be done as shown below:
Molar mass of CoF2 = 59 + (19x2) = 97g/mol.
The percentage composition of cobalt in cobalt(II) fluoride, CoF2 is given by:
Mass of Co/Molar Mass of CoF2 x 100
=> 59/97 x 100 = 60.8%
Therefore, the percentage composition of cobalt in cobalt(II) fluoride, CoF2 is 60.8%
Why is fusion not used to generate electrical power ?
Answer:
Fusion doesn't produce runway chain reactions the way fission can, so there's no need to worry about meltdowns.
In the graph above for the dissociation of a strong acid, why do the bars for H3O+ and A- have the same height as the bar for HA?
Answer:
The concentration of HA is the same as concentration of H3O+ and A- produced.
Explanation:
The dissociation equation is given below:
HA(aq) + H2O (l) —> H3O+(aq) + A-(aq)
From the reaction above, we can see that the acid is monoprotic acid i.e it has only 1 ionisable hydrogen atom.
Now, from the balanced equation, we can see that the acid produced equal concentration of H3O+ and A-.
This account for the reason why the bars for H3O+ and A- have the same height as the bar for HA.
What is the % of each element in Ni3{PO4) 2 ?
Answer:
nickel 48.1063%
Phosphorus 16.9245%
Oxygen 34.9692%
The percent composition of each element like nitrogen, oxygen and phosphorous in Ni₃(PO₄)₂ are 48.03%, 34.97% and 16.93% respectively.
How do we calculate % composition?Percent composition of any element present in any compound will be calculated as:
% comosition = (Mass of element / Mass of compound)×100%
Mass of Ni₃(PO₄)₂ compound = 366.02 g/mol
Molar mass of 3 Nitrogen atoms = 3×58.6 = 175.8 g/mol
Moar mass of 2 Phosphorous atoms = 2×31 = 62 g/mol
Moar mass of 8 Oxygen atoms = 8×16 = 128 g/mol
% comosition of Nitrogen = (175.8/366.02)×100% = 48.03%
% comosition of Oxygen = (128/366.02)×100% = 34.97%
% comosition of Phosphorous = (62/366.02)×100% = 16.93%
Hence % composition of nitrogen, oxygen and phosphorous is 48.03%, 34.97% and 16.93% respectively.
To know more about percent composition, visit the below link:
https://brainly.com/question/21044245
What is the overall reduction potential for the reaction Agt (aq) + Cu(s)——>Ag(s) + Cu2+ (aq)?
-0.46 V
+0.46 V
+0.57 v
+1.14V
Answer:
it should be +0.46 :)
Explanation:
I just took the test and got it right.
Answer:
I think it's +1.14 V, but don't take my word for it..
What mass of water will be collected if 20.0
grams of hydrogen are consumed
2H2+O2--->2H2O
358g
179g
44.7g
Or 89.4g
Answer: 179 of [tex]H_2O[/tex] will be produced.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} H_2=\frac{20.0g}{2.01g/mol}=9.95moles[/tex]
[tex]2H_2+O_2(g)\rightarrow 2H_2O[/tex]
According to stoichiometry :
2 moles of [tex]H_2[/tex] give = 2 moles of [tex]H_2O[/tex]
Thus 9.95 moles of [tex]H_2[/tex] will require=[tex]\frac{2}{2}\times 9.95=9.95moles[/tex] of [tex]H_2O[/tex]
Mass of [tex]H_2O=moles\times {\text {Molar mass}}=9.95moles\times 18g/mol=179g[/tex]
Thus 179 of [tex]H_2O[/tex] will be produced.
5. On what organ does alcohol have the most noticeable effect?
Answer:
the liver
Explanation:
it processes alcohol, work very hard
What is the mass of 3.00 moles of carbon
Answer:
36 grams as 1 mole is 12 grams
Answer:
tbh idk cause I will love to answer your question but ehh
Given:
CH4 + 2O2 → CO2 + 2H2O, ΔH = -890 kJ/mol
How much energy is released when 59.7 grams of methane (CH4) reacts with oxygen?
The combustion of 59.7 grams of methane releases ____ kilojoules of energy
Answer:
The combustion of 59.7 grams of methane releases 3320.81 kilojoules of energy
Explanation:
Given;
CH₄ + 2O₂ → CO₂ + 2H₂O, ΔH = -890 kJ/mol
From the combustion reaction above, it can be observed that;
1 mole of methane (CH₄) released 890 kilojoules of energy.
Now, we convert 59.7 grams of methane to moles
CH₄ = 12 + (1x4) = 16 g/mol
59.7 g of CH₄ [tex]= \frac{59.7}{16} = 3.73125 \ moles[/tex]
1 mole of methane (CH₄) released 890 kilojoules of energy
3.73125 moles of methane (CH₄) will release ?
= 3.73125 moles x -890 kJ/mol
= -3320.81 kJ
Therefore, the combustion of 59.7 grams of methane releases 3320.81 kilojoules of energy
Answer:
The combustion will release -3,321 KJ/mol of energy
Explanation:
When humans plant more trees, carbon can begin entering the ____
a- hydrosphere
b- geosphere
c- biosphere
Answer:
biosphere
Explanation:
The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere and atmosphere of the Earth.
The biosphere refers to the regions of the surface and atmosphere of the earth or another planet occupied by living organisms.
Plants are responsible for taking in carbon in nature. When more trees are planted, carbon is absorbed by plants which is a component of the biosphere. Hence planting more trees means increasing the intake of carbon into the biosphere.